Hello I have used my bucket three times now and always pre washed with pbw and star san and as well as right after racking but I can’t seem to get these stains out afterwards it’s is only around the krausen line is this normal for stainless steel fermenters?
BKF would likely work, I'd have suggested PBW but in the end I'm sure they'll be the same results. Either should do it depending on which you have, or if you have both try both.